Microarray analysis reveals altered expression of a large number of nuclear genes in developing cytoplasmic male sterile Brassica napus flowers
Microarray analysis reveals altered expression of a large number of nuclear genes in developing cytoplasmic male sterile Brassica napus flowers
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DOI：
10.1111/j.1365-313x.2006.02975.x
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发表时间：
2007-02-01
期刊：
影响因子：
7.2
通讯作者：
Glimelius, Kristina
中科院分区：
文献类型：
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作者：
Carlsson, Jenny;Lagercrantz, Ulf;Glimelius, Kristina
为了对油菜细胞质雄性不育（CMS）的机理有新的认识，我们比较了甘蓝型油菜细胞质雄性不育系与可育B花的核基因表达谱。利用拟南芥花特异性cDNA微阵列对甘蓝型油菜保持系进行分析。所用CMS系具有B。napus核基因组，但具有重排的线粒体（mt）基因组，其由两个B组成。napus和A.拟南芥DNA基因表达谱分析表明，大量的基因在两个线之间的表达不同。例如，与B相比，CMS系中编码参与蛋白质输入细胞器的蛋白质的核基因、在雄蕊和花粉中表达的基因以及涉及细胞壁重塑或结构的基因被抑制。油菜。这些结果表明，不育系的mt基因组强烈影响核基因的表达，从而揭示了线粒体和细胞核之间的逆行信号的重要性。此外，CMS系的花的特征在于雄蕊被心皮状器官替代，因此部分类似于APETALA 3（AP 3）和PISTILLATA（PI）突变体。根据这种表型，AP 3表达下调雄蕊，不久之前，这些器官发展心皮状特征，即使它是正确的启动。PI的抑制成功的AP 3，可能是一个后果的损失AP 3的活动。这些结果表明，AP 3在雄蕊中的表达依赖于适当的mt功能和正确的核-mt相互作用，mt的改变导致不育系的雄性不育表型。
To gain new insights into the mechanism underlying cytoplasmic male sterility (CMS), we compared the nuclear gene expression profiles of flowers of a Brassica napus CMS line with that of the fertile B. napus maintainer line using Arabidopsis thaliana flower-specific cDNA microarrays. The CMS line used has a B. napus nuclear genome, but has a rearranged mitochondrial (mt) genome consisting of both B. napus and A. thaliana DNA. Gene expression profiling revealed that a large number of genes differed in expression between the two lines. For example, nuclear genes coding for proteins that are involved in protein import into organelles, genes expressed in stamens and pollen, as well as genes implicated in either cell-wall remodeling or architecture, were repressed in the CMS line compared with B. napus. These results show that the mt genome of the CMS line strongly influences nuclear gene expression, and thus reveal the importance of retrograde signalling between the mitochondria and the nucleus. Furthermore, flowers of the CMS line are characterized by a replacement of stamens with carpelloid organs, and thus partially resemble the APETALA3 (AP3) and PISTILLATA (PI) mutants. In accordance with this phenotype, AP3 expression was downregulated in the stamens, shortly before these organs developed carpelloid characteristics, even though it was initiated correctly. Repression of PI succeeded that of AP3 and might be a consequence of a loss of AP3 activity. These results suggest that AP3 expression in stamens depends on proper mt function and a correct nuclear-mt interaction, and that mt alterations cause the male sterility phenotype of the CMS line.